Annual report of the Canal Zone Plant Introduction Gardens

ANNUAL REPORT

OF THE

CANAL ZONE

Plant Introduction
Gardens"

For the Fiscal Year
1929

Since the writing of this Report, announcement has been made of
the change in name to
"CANAL ZONE EXPERIMENT GARDENS"

THE PA

MOUNT HOPE, C

0

OREGON

RULE

CO.

1

U.S.A.

t- 2

3

5

OO-51-L

ANNUAL REPORT

OF THE

CANAL ZONE

Plant Introduction
Gardens*

For the Fiscal Year
1929

* Since the writing of this Report, announcement has been made of

the change in name to

"CANAL ZONE EXPERIMENT GARDENS"

THE PANAMA CANAL PRESS
MOUNT HOPE, C. Z.

1 930

For additional copies of this publication address The Panama Canal, Washington,
or Balboa Heights, Canal Zone.

D. C.

LETTER OF TRANSMITTAL.

Canal Zone Plant Introduction Gardens,

Summit, C. Z., July jiy 1929.

Sir: I have the honor to present herewith and to recommend for
publication, a condensed statement of the Annual Report of the Canal
Zone Plant Introduction Gardens, for the year ending June 30, 1929.

Respectfully,

J. E. HlGGINS,

Agronomist in Charge.
Mr. Roy R. Watson,

Chief Quartermaster ;

Balboa Heights, Canal Zone.
Through Mr. J. H. K. Humphrey,

Assistant Chief Quartermaster.

CONTENTS.

Page.

Introduction „ 7

Plant Collecting in Hawaii and California 8

The Itinerary „ - 8

In California _ 9

Avocado Varieties. 9

Establishing Exchange Relations 10

In Hawaii 1 1

Sugar Cane 12

The Pineapple.— 13

The Avocado 14

Hibiscus Varieties 14

General Shipments of Plants 14

Acknowledgments 18

Other Important Plant Introductions 18

Plant Disseminations 19

The Mango..... 20

Sugar Cane 25

Rice 25

Rubber Plants 26

Drought Resistant Trees 26

Towns and Roadside Plantings. 27

Synthetic Manures _ 30

Buildings 30

The Needed Irrigation System 31

ILLUSTRATIONS.

PLATES.

Plate I Figure i. A cane plantation in Hawaii.

Figure 2. A near view of cane as it grows in Hawaii.

Plate II Figure 1. A pineapple plant breeding station in Hawaii.

Figure 2. A plant selection field, operated by one of the large pineapple
companies.

Plate III Figure 1. Banana corms for shipment, after being pruned and dried for a
period of several weeks.
Figure 2. Four Wardian cases of plants, on the top deck of the U. S. A. T.
Somme.

Plate IV Figure 1. "Australian Oak," Casuarina Sp.y heavily pruned and effectively
used as a windbreak.
Figure 2. A fine specimen oi Hala, Pandunus tectorius, from which Hawaiian
mats are made.

Plate V Figure 1. Bignonia Unguis-cati, a magnificent vine which becomes a veritable
cloth of gold, when in flower.
Figure 2. Two species of Araucaria.

Plate VI Figure 1. An effective piece of tropical landscape gardening in Honolulu.
Figure 2. Another tropical effect in the grounds of the Royal Hawaiian
Hotel.

Plate VII The Fairchild mango.

Plate VIII The Queen pineapple.

Plate IX Figure 1. Cassia nodosa in flower.

Figure 2. Interior view of plant house showing type of construction.

Plate X Figure 1. Corotu tree, Enterolobium cyclocarpum, showing defective branch-
ing habit.
Figure 2. Corotu tree, showing splitting due to defective attachment of
branches.

ANNUAL REPORT

OF THE

CANAL ZONE PLANT INTRODUCTION
GARDENS FOR 1929

BY

J. Edgar Higgins, Agronomist in Charge.

Introduction.

The work of the Canal Zone Plant Introduction Gardens has been
continued throughout the year along the same general lines as outlined
in the Annual Report for 1928. The aims and objectives of the work
were quite fully set forth in that report. Increasing emphasis is being
laid upon such effort in plant introduction and experimentation as
may prove to be of permanent value, not only to the Canal Zone, but
to Panama in general, and ultimately to the entire surrounding region.
This is understood to be the definite purpose of the Administration in
maintaining this work. As an illustration, mention may be made of
the introduction, propagation, and dissemination of the varieties of
sugar cane. The sugar industry in Panama is at present suffering much
from the Mosaic disease and other pests. There is need of varieties of
cane resistant to this disease and also of higher sugar-yielding capacity.
The Gardens have introduced many varieties, including a number that
have proved satisfactory in other countries. This year sample lots for
testing under plantation conditions have been distributed without
charge to the Government of Panama and to private growers of cane in
the Republic. This work is being still further pursued by the introduc-
tion of other varieties and by the increasing of the plantings at the
Gardens so that the dissemination of any selected varieties may be
extended.

Panama imports large quantities of rice, a commodity which it would
seem, should be produced more abundantly in the Republic. The
Gardens have introduced many varieties from the Philippines and else-
where, especially of upland rices, and this year are offering these to the
Government of Panama and to individuals for trial.

While the emphasis is thus placed upon those things which give most
promise of presenting economic results, the fact is never overlooked
that it is impossible to foresee fully the future, and plants which may
have been introduced for their general interest or for their ornamental
value may become of economic importance also. The African Oil
Palm, Elaeis guineensis, was probably introduced chiefly as an orna-
mental, yet with the increasing devastation of disease among the coco-
nuts of this region, it is not impossible that this palm may become of
large economic significance as a source of vegetable oil. Other examples
of the same character might be cited. Also the importance of purely
ornamental plants can not be overlooked. They are of educational
value, add to the general interest of life for those who reside here, and
are an attraction to travelers. The opportunities for making the
Canal Zone a garden spot at the Crossroads of the World are unlimited.
Therefore, many plants of general interest are being added constantly
to the Garden accessions.

Plant Collecting in Hawaii and California.

During the year just closed, the Agronomist made an extended trip
to Hawaii to collect seeds and plants, and a brief side trip to Southern
California, the chief purpose of the latter being the acquiring of new
varieties of avocado and the establishing of exchange relations with
organizations interested in plant life. The record of this trip, because
of its importance, may constitute a considerable part of the present
Annual Report. This travel was performed in compliance with the
letter of authorization of the Governor of the Panama Canal, issued
September 10, 1928, in accordance with the recommendation of the
Chief Quartermaster. The general purposes of the trip were those
which the Government of the Canal, with much foresight, designed in
the establishment of the Plant Introduction Gardens, namely the intro-
duction of useful and ornamental plants for the improvement of the
Canal Zone and, through it, of this entire region. The specific objects
of this trip will be brought out a little later in a discussion of the work
performed in the two countries mentioned.

The Itinerary.

The embarkation was from Balboa, on September 13, 1928, on the
U. S. A. T. U. S. Grants which arrived at San Francisco, September 24.
I remained in California until October 31, a period of 37 days, during
which 20 days of accrued leave were taken, awaiting the sailing from
San Francisco of the next Army Transport, from the Canal en route to

Hawaii. This transport, the Chateau Thierry, which brought a small
shipment of Canal Zone plants for Honolulu and also Wardian cases for
use on the return shipment of plants, left San Francisco on October 31
and arrived at Honolulu in the evening of November 6. By the schedule
which had been arranged, it was intended to make the return trip by
the U. S. A. T. Cambrai. As this ship was unavoidably removed from
her regular schedule, I embraced the first opportunity to return with the
plants from Hawaii on a through boat, which opportunity was afforded
by the sailing of the U. S. A. T. Somme from Honolulu on January 11,
1929. The Somme remained in San Francisco from January 18 to
January 25, and arrived in Cristobal on February 4, 1929.

In California,
avocado varieties.

In immediate plant collecting in California, the chief objective was
the securing of bud-wood of certain varieties of avocado. Although
California has been engaged in avocado culture for a comparatively
short time, there probably is no other place in the world where there
has been so much activity in recent years in the improvement of the
culture of this crop. Large commercial orchards have been planted and
the growing and marketing of the fruit are being established upon a
strong basis. Hundreds of varieties have been under test, including
those introduced from tropical countries and those that have originated
within the state. It was desired to get the latest information as to the
behavior of these and to introduce such as might be of promise for Canal
Zone conditions, and also any that may do well in the higher altitudes of
the Republic of Panama. By all of these means, it is expected that a
continuous supply of choice avocados can be made available throughout
the year. At present the markets are flooded, for a brief period, with
fruit, most of which is of very poor quality, and this is followed by a
period of scarcity which lasts the greater part of the year. Already we
have varieties which are demonstrating their adaptability to fill a part
of this gap in the seasons.

There were collected in California, and shipped by mail to the Canal
Zone Gardens, bud-sticks of avocados of the following varieties: Ishim,
Murrieta Green, Linda, Sharpless, McArthur, Genesta, Cantel, Dickey,
Northrop, Nabal, Benik, Cabnal, Fuerte Seedling, Lyon Seedling,
Ishim Seedling, Spinks, Murrieta Two pounds.

These varieties are all new to the Zone or the propagating material
collected represents a strain which was considered worthy of trial.

10

The method of packing this bud-wood for shipment may be worthy of
record as the material arrived in excellent condition. The method is
essentially the same as that which was successfully used by the writer
in an experimental shipment of avocado buds from California to Manila
in the year 1926. Strong and fairly mature bud-wood was selected.
With the least exposure possible, it was cut into suitable lengths and the
ends of each piece were dipped in warm paraffin. Each piece was then
wrapped separately in a very thin wax paper of the weight usually sold as
sandwich paper. This appears to be of considerable value for the long
distance shipment of avocado bud sticks, which are essentially green,
tender, and subject to bruising and decay. These separate sticks were
then combined into bundles of four to six with a wrapping of a slightly
heavier grade of wax paper. The packing moss was prepared by soaking
a quantity of sphagnum in water, wringing out all the water possible and
adding a sufficient bulk of perfectly dry, finely divided moss to give the
proper moisture content. The great damage arises out of having too
much moisture in the mixture. The right proportions can be approxi-
mated by dividing the entire bulk of moss into two equal parts, wetting
one-half and leaving the other half dry to be thoroughly mixed with the
moist half after the latter has been made as dry as possible by wringing
in burlap sacking. A heavy paper box, a few inches longer than the
bud-stick packages, was provided and lined with heavy wax paper which
could be folded over the top when the box was filled. A layer of the
moss was placed in the bottom of the box on the wax-paper lining. Over
this moss a layer of bud-stick packages, prepared as indicated above,
was placed and covered with more moss. More bud-stick packages
were then put in and thus the packing was continued until the box was
filled. The contents were pressed down slightly but not too tight, the
heavy wax-paper lining was drawn over the top so as to make the pack-
age as nearly air-tight as possible and the box was closed, wrapped with
another heavy wax paper and finally with a manila wrapper and was
tied securely. It was then ready for mailing. The purpose of all of
this is to retain the natural moisture in the bud sticks without bringing
additional moisture in contact with them, and without permitting them
to become bruised by rubbing together. By the use of these methods
the avocado buds arrived at the Isthmus in excellent condition.

ESTABLISHING EXCHANGE RELATIONS.

A further objective of the work in California was the establishing of
exchange relations with the California Botanic Gardens, now being
organized, and with other institutions or individuals interested in plant
exchange.

11

The site for these gardens is a magnificent one, located in a valley
near Santa Monica. Over 1,000 acres of land have been set aside
for the use of the Gardens in this unusually warm and well-protected
valley. Very large endowments are being arranged and those in charge
of the project are expecting to develop one of the largest botanic
gardens in the world. Botanists and horticulturists representing the
organization are collecting plants and seeds in various parts of the
tropics and subtropics. This institution and the Canal Zone Plant
Introduction Gardens seem particularly able to be of mutual assistance
through cooperation. The California Botanic Gardens will introduce
from tropical countries many species and varieties of plants. In many
instances there may be a greater quantity of seed than will be required
for the first planting. Some of the tropical plants may require several
attempts to establish them in California and the first plants grown may
fail, while young, from an occasional brief period of cold weather. In
such cases, if the species have become established in the Canal Zone
Gardens, where there is no cold-weather hazard, it would be a compara-
tively easy matter to send to California new propagating material for a
second or a third attempt to adapt it to California conditions. The
unusual opportunities for mutual assistance and cooperation which are
thus opened up by the relationships of these two Gardens are now well
recognized by both institutions and some exchanges have been begun.
In this way, as well as in the transmitting of seed and plants native to
Panama, or received from our numerous exchanges throughout the
tropics, the Canal Gardens, may render a helpful service. At the same
time, the benefits accruing to the Canal Zone Gardens will be equally
great, or greater.

Several visits were made to the California Botanic Gardens to become
familiar with the work, now just beginning, and it was our privilege to
have several conferences with the officials representing the organization.

Commercial gardens which have specialized in rare and unusual plants
were visited. Many things of interest were seen in these, some of
which will be introduced later for trial at the Isthmus.

In Hawaii.

In Hawaii a varied collection of plants was secured. This island
group has been in plant introduction work for many years and also in the
work of breeding new varieties of plants. The bringing in of new plants
was begun by private citizens in the early years, and has since been
carried on by the Government and by privately-controlled experiment

12

stations. Hawaii is well equipped with experiment stations and similiar
agricultural institutions. These include the Hawaii Agricultural Ex-
periment Station under the control of the Federal Department of
Agriculture, the Territorial Board of Agriculture and Forrestry, the
Agricultural Experiment Station of the University of Hawaii, the
Experiment Station of the Hawaiian Sugar Planters Association, and the
Experiment Station of the Association of Hawaiian Pineapple Canners.
All of these and other institutions have engaged in plant introduction
or plant breeding, or both.

SUGAR CANE.

Hawaii is first a sugar-producing country, the little group of islands
now producing over 800,000 tons of sugar per year, and rapidly approach-
ing the one million mark. (Plate I, Figures 1 and 2.) It probably
leads the world in the yield of sugar per acre, the average in 1928 for all
plantations, including unirrigated as well as irrigated, being 6.67 tons
per acre, while yields of 1 5 tons of sugar per acre and above are frequently
recorded. These phenomenal yields are largely due to the appli-
cation of science and engineering skill to the many problems that enter
into the industry, from the breeding of new varieties of cane, the liberal,
but well measured use of fertilizers and water, the increased efficiency
in the application of water, and all other agricultural aspects of pro-
duction to the last step in the manufacture and the marketing of the
sugar. When their older canes have not proved equal to new con-
ditions the Hawaiian Sugar Planters, through their Experiment Station,
have developed new varieties to meet the situation. The now famous
variety H-109, is doubtless to be credited with a very large part of
increased yields of the last decade.

One of the purposes of the trip to Hawaii was to secure a collection
of the most promising canes for trial in Panama where new and disease-
resistant varieties are greatly needed. As the season was not opportune
for the getting of these canes at that time and was likewise most in-
opportune for the planting of the same at the Canal Zone Gardens,
arrangements were made, through the cooperation of the Experiment
Station of the Hawaiian Sugar Planters' Association, and particularly
through the courtesy of Dr. Harold L. Lyon, for the shipment of such
a collection of canes, to arrive here at the beginning of the rainy season.
This shipment, which was prepared and packed with the utmost care
by the Agricultural Department of the Experiment Station, received
every attention possible to insure the exclusion of all insects and diseases
and to maintain the cuttings in perfect health en route. All the canes

PLATE I.

Fig. 1. — A cane plantation in Hawaii.

*

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t / m An mt \ -*VaA*

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v

*

FlG. 2. — A near view "I cane as it throws in H

tirows in nawan.

p. 12— a.

PLATE II.

Fig. 1. — A pineapple plant breeding station in Hawai

F i'.. 1. A plant selection field, operated by one of the large pineapple companies
p. 12 -b.

ERRATUM.

The two illustrations composing Plate II have
been reversed. That shown at the top of the page is "A
plant selection field" and the other is "A pineapple
plant breeding station."

13

arrived at Balboa on May 31, 1929, in perfect condition and were im-
mediately planted. The shipment included varieties as follows:

Stripe Mexican.

Yellow Calidonia.

H-8965.

Stripe Tip.

Lahaina.

Badila.

H-109.

26 C 250.

U. D. 1.

Hawaiian Uba

P. 0. J. 36

P. 0. J. 213

D-1135.

THE PINEAPPLE.

But the pineapple, in Hawaii, has become second only to sugar cane
in importance and, in a little more than 25 years from humble begin-
nings, has attained an annual production approaching 9,000,000 cases
of canned fruit. This industry also has been fostered by the liberal
expenditure of funds in the investigation of every phase of pineapple
production, packing, and marketing. While selected strains of the
Cayenne variety continue to be the basis of the industry, many other
introduced varieties are under close observation, and thousands of new
seedling and hybrid varieties have been produced in the effort to be
prepared for all emergencies and to take advantage of any superior
forms that may appear. (Plate II, Figures 1 and 2.)

All of this has its bearing upon Panama and Tropical America in
general, as possible pineapple producing countries of the future; and
this, without competing with Hawaiian producers, who frankly admit
they must look outside of the limits of Hawaii for lands upon which
to expand the industry, and who would gladly enter the Americas if
these regions prove to be best adapted to their business. As pineapple
packers buy large quantities of fruit from private growers, the presence
of a cannery would make a market for all the fruit that the native
growers might produce and would bring large sums of money into the
country.

Therefore, another of the principal objects of the trip to Hawaii was
to arrange for the securing of a liberal supply of plants of the Cayenne
variety and small amounts of planting material of a number of other
varieties. The best time to secure pineapple plants in Hawaii is about
midsummer, and, as this fits in satisfactorily with the planting season
for the Canal Zone, it was arranged to have the shipments come forward
about August. Several thousand plants of Cayenne are being pur-
chased for the shipment. We are indebted to Dr. Frederic G. Krauss,
head of the Extension Division of the University of Hawaii and
Geneticist of the Experiment Station of the Association of Hawaiian
Pineapple Canners, for his offer to complete arrangements for this
shipment.

14

THE AVOCADO.

In Hawaii, the avocado was again one of the important objects of
search. A decade or two ago Hawaii was almost as poorly supplied with
Fall and Winter avocados as Panama is to-day, but the introduction or
the breeding of new varieties, chiefly of the Guatemalan race, and the
production of the hybrids of the West Indian and Guatemalan races,
are rapidly changing this situation. Now, some of the best avocados of
the year are available during these seasons. Buds of many of these
varieties and also choice varieties of summer avocados were secured and
were forwarded by mail to the Canal Zone. These varieties include the
following: Lahi, Esbank, Cooper, Kanola, Gulick Green, Gulick Red,
Bountiful, Kinau, Beardslee, Inezholt x Wilder, Haley, Wilder, Aubrey,
Hulumanu, Itzamna, Enoi, Bon, Prize Lahaina, Sexton, Bromley, and
Seyde.

HIBISCUS VARIETIES.

In the breeding of ornamental plants, Hawaii has specialized in the
Hibiscus, and from about a dozen varieties has bred a bewildering
assortment running into the thousands of varied forms and colors.
Many of these are of exquisite beauty, and among them are included,
not only singles, but all degrees of double flowers. There are single and
double pure white flowers of large size, single and double yellows, reds,
and pinks in innumerable varied combinations. Many of these have
never been adequately described and recorded and hence have no
established and recognized names. Several hundreds of cuttings of
many varieties were collected and mailed to the Canal Zone. The
new sorts will add greatly to the variety of form and color in hibiscus on
the Isthmus.

General Shipments of Plants.

Several shipments of seeds or other propagating material of many
different species were despatched by mail from Honolulu. On the
return trip of the U. S. A. T. Somme were brought four Wardian cases 1
of growing plants (Plate III, Figure 2), and 10 crates and boxes of
cuttings, seeds, corms, or other propagating material, in a quiescent
condition, and which thus could be carried below decks. Brief mention
will be made of a few of the kinds of plants in these shipments.

■ A Wardian case is a device for shipping plants long distances. It is essentially a closed box
or case, with a roof-shaped top, covered with jdass which is protected by wooden slats. It is venti-
lated by only a small opening in each end of the case. The device affords protection from salt spray
and -troiiK winds, and obviates the necessity of frequent watering as the water has bat little opportunity
to ew ape. and that which is transpired by the plants is condensed and again used by the plants. Moist
01088 placed about the pots also aids in maintaining the moisture supply.

PLATE III.

Fig. 1. — Banana corms for shipment, after being pruned and dried for a period of several weeks.

Fig. 2. Four Wardian case's of plants on the top deck of tin- U. S. A. T. Somi

p. 14 a.

15

BAXAXAS.

The banana varieties in this shipment may prove to be of much im-
portance. The Hawaiian cooking banana is of very superior quality,
surpassing most if not all of the plantains of the West Indies and Central
America. The shape of the bunch and the toughness of the skin also
make it a good fruit for shipping. There are several varieties of this
group known as the Maoli or native banana. They are all characterized
by thick and rather blunt or rounded ends of the individual fruits or
"fingers" which also tend to lie rather close to the stem of the bunch.
Of this group there are being introduced, in this shipment, the following
varieties: Maoli, which gives the name to the group, Kaualau, Manaiula,
and Ae-ae. Other Hawaiian bananas in the present introductions are
the Iholena, Lele, Puapuanui, Koae, Mahoe, Popoulu, Manaikea, Iho-u,
and the Maia Huaalua. Although these latter are not usually regarded
as well adapted to commercial culture, they are highly prized as special-
ties for the home garden or banana collection.

The method of shipping the propagating material of these bananas
may be of interest. In the shipment which was brought on the trans-
port Somme, large corms, nearly ready to "shoot," were used. The
entire top of the plant was cut off about six to eight inches above the
corm and all roots were cut close to the corm. All soil, and all decaying
material were removed, and the remaining parts were placed under the
edge of a shed where they were exposed to direct sunlight during a part
of each day for a period of about three weeks. As the leaf bases de-
cayed, or became dry, they were removed close to the solid tissue of the
corm. Plate III, Figure i shows this shipment ready for crating.
There was thus as little as possible left to bvite decay. These thorough-
ly dried corms were wrapped in dry excelsior, and packed in crates
provided with slats about one and one-half inches apart, thus permit-
ting free ventilation. The crates were placed in the hold of the ship,
and remained there continuously, except in the port of San Francisco,
where they were removed to the dock with all other plant shipments
except those in Wardian cases, and were covered with tarpaulin while
the ship was being fumigated.

The weather in San Francisco at the time was unusually cold, and
even with the heavy tarpaulin covers it was feared that the bananas and
other delicate plants would be injured by the low temperatures. The
Wardian cases, by the special courtesy of the Army transport authorities,
had been placed on the hospital deck and protected by awnings and
tarpaulins when necessary. In San Francisco these cases were wrapped

16

at night in several thicknesses of woolen blankets and of tarpaulins, and
in the daytime were exposed to the light. By these precautions, it was
possible to avoid any injury by cold weather.

On arrival at the Isthmus, the large well-developed corms of bananas
that had been prepared, as indicated above, were found to be in excellent
condition. A later shipment of smaller corms, and slightly less dried,
showed more losses.

OTHER PLANTS OF SPECIAL INTEREST.

The Hawaiian Fig. — A variety of fig, producing a very fine quality
of fruit, has been grown in Hawaii for many years, and yields well,
even at sea level. As this fig seems to be well adapted to the tropical
conditions, under which most figs do not prosper, several of these plants
were included in the shipment tor trial in the Canal Zone, and also in
Panama.

Casuarina torulosa. — One of the so-called "Australian Oaks," is another
of the introductions from Hawaii that may be of value on the Isthmus.
It resembles C. equisetifolia, the species with which many residents of
the Canal Zone are familiar, under the name "Australian Oak" or "Pine"
tree, although it is neither a pine nor an oak. A considerable quantity
of seed of Casuarina torulosa was brought in and has grown well. Plate
IV, Figure i, shows one of the species of casuarina, heavily pruned, and
used as a windbreak close to the sea, and exposed to the wind.

Grape. — A strain of the Isabella grape, which was probably brought
to Hawaii from the Madeira Islands many years ago, is another temper-
ate zone or subtropical fruit which has long prospered under the tropical
conditions of Hawaii, and often produces two crops per year. Plants and
cuttings were brought from Hawaii, and are being tried at the Gardens,
and in Panama. Some of these are being sent to the higher altitudes of
the Province of Chiriqui.

Queens/and Nut. — Several pounds of seed of the Australian or Queens-
land Nut, Macadamia ternifolia, were included, and have germinated
well. This, which is recognized to be one of the best nuts grown in the
tropics, is now being planted commercially in Hawaii. It is well worthy
of trial in the Isthmus at all altitudes from sea level to 5,000 feet.

The Solo Papaya. — The Solo variety of papaya, although small, is
perhaps the best in flavor of all the papayas. It also acquires a good
yellow color while still firm, and thus makes an attractive appearance.
The flesh is also of attractive yellow color, and unsurpassed in texture.
It may be spooned out to the skin without waste. The placenta to which
the seeds are attached is easily removed, leaving the flesh clean and unim-

PLATE IV.

Frc. I. — "Australian Oak," Causuarina, .^/j.,* heavily pruned and effectively used as a windbreak.

Fig. 2. — A fine specimen of Hala, Pandanus tectorius, from which Hawaiian mats are made.

p. 16— a.

o Q

e -
go

^

■SB

h

p. 16— b.

17

paired. These characters appear to be reproduced quite accurately by
seed although the shape of the fruits is somewhat varied. The Solo
has been cultivated in Hawaii for about 15 years, and retains its high
quality. It is now being grown commercially for special markets,
and is frequently shipped in corrugated paper boxes with individual
compartments. Several hundreds of the plants, from the seed brought
from Hawaii, already have been disseminated, and others are being
planted at the Gardens.

Oleanders. — Mention should be made of a collection of varieties of
oleanders. These included a large dark red, small dark red, pale cream,
single pink, semidouble pink, semidouble white, and others. These
should add much to the variety of flowering shrubs in the Isthmus, as the
oleander thrives under the conditions here, and if well cared for and prop-
erly pruned makes a handsome appearance. At present the oleanders
are but little used here and the varieties are few.

Bignay, Antidesma bunius, is a fruit tree of the Orient well worthy of
a place in Central America. The tree is of medium size and rather
dense growth, with dark-green foliage. It yields profusely small clusters
of dark-red fruits much used in the Philippines for the making of fruit
punch and jelly, both of which are very attractive in appearance and
in flavor.

Among other ornamental plants worthy of special notice may be
mentioned the very large flowered Allamanda cathartica var. Hendersonii,
with its thick shiny-green leaves and yellow flowers, about twice as large
as those of the variety now common in this country.

Another interesting and beautiful vine is Holmskioldia sanguinea,
the so-called Parasol-Flower. This is a rather vigorous climber bearing
a profusion of small flowers, resembling miniature parasols. In the
distance the color effect resembles that of the brick-red Bougainvillea.

Solandr a guttata, the Golden Cup, is of striking and unusual appearance.
It is a strong climber with heavy dark-green leaves, and large yellow
goblet-shaped flowers of delicate perfume.

Nymphaea. — The Gardens' collection of Nymphaeas or water lilies
was augmented by a pink variety, and by a blue.

Plumeria. — Several varieties of Plumeria or Frangipanni were included
in the new introductions.

Bignonia unguis-cati (B. Tweediana, Lindl.) the Cat's-Claw climber
(Plate V, Figure 1) is well adapted to the covering of concrete or stone
walls, and in Hawaii is much used on buildings of concrete or stone. It
also is allowed to climb on some kinds of trees and on dead tree trunks.

Similar descriptive notes might be recorded in relation to many of
the other species on the list of introductions. Plates IV, V, and VI
show some of the interesting useful and ornamental plants of Hawaii.

18
Acknowledgments.

Our indebtedness to the Experiment Stations of the Hawaiian Sugar
Planters' Association, and of the Association of Hawaiian Pineapple
Packers in connection with the cane and pineapple introductions, al-
ready has been mentioned. Equally helpful was the assistance rendered
by the Federal Agricultural Experiment Station, the University of
Hawaii, and the Territorial Board of Agriculture and Forestry. Thanks
are due personally to Dr. Harold L. Lyon and Mr. J. E. Wist, of the
Hawaiian Sugar Planters' Station, to Director James M. Westgate and
Dr. Willis T. Pope, of the Federal Station, to Mr. David T. Fullaway
and Mr. H. A. Whitney, representatives of the Federal Horticultural
Board, to Mr. Charles S. Judd and Mr. David Haughs, of the Terri-
torial Board of Agriculture and Forestry, whose close cooperation very
greatly assisted the work, to Mrs. John Walker, for a collection of rare
varieties of hibiscus, and to Mr. and Mrs. William J. Cooper, who
donated a large collection of propagating material of avocado and of
selected hibiscus varieties, including several originated by Mrs. Cooper.

Special thanks are due to Major General Malin Craig, commanding
the Panama Canal Department, to Major General Fox Conner, com-
manding the Hawaiian Department, and to numerous others of the
Army in Hawaii and the Canal Zone, as well as to the officers of the
several U. S. Army transports concerned in these shipments. The
transportation problem was very greatly simplified by the complete
cooperation of all of these gentlemen, and the special care which was
given to the plants which by this means it was possible to ship through
on one boat from Honolulu to Cristobal without transfer.

Other Important Plant Introductions of the Year.

The Gardens were again fortunate in receiving, on March 29th, a large
contribution of plants from the yacht Utawatia. Mr. Allison Vincent
Armour, who has done much to further the interests of plant introduction
in America by expeditions with his yacht, and Dr. Thomas Barbour,
made a winter trip, circuiting the Caribbean region. Calls were made
at many ports and several important botanic gardens were visited. The
collection of plants thus brought to the Canal Zone Gardens included
the following:

PLATE VI.

Fig. 1. — An effective piece of landscape gardening in Honolulu.

P"lG. 2. — A lother tropical effect in the grounds of the Royal Hawaiian Hotel.

p. IX a.

19

Species or variety.

Species or variety.

Schwartzia grandiflora 12 plants.

Marcgravia Hartii 25 cuttings.

Amherstia nobilis 1 plant.

Congea tomentosa 1 plant.

Congea sp 1 plant.

Eugenia caryophyllata 5 plants.

Copernicia cerifera 1 plant.

Eperua falcata 1 plant.

Adhatoda 1 plant.

Unidentified 1 plant.

Stevensonia grandiflora 1 plant.

Thevetia nereifolia 1 plant.

Corypha umbraculiferae 6 plants.

Hyophorbe verschaffeltia 1 plant.

Areca madagascariensis 1 plant.

Bertholletia excelsa 2 plants.

Caryocar nuciferum.... 2 plants.

Monodora ternifolia 1 plant.

Pongamia glabra 1 plant.

Putranjiva roxburghiana 2 plants.

Bentinckia nicobarica... 2 plants.

Ptychoraphis augusta 2 plants.

Garcinia mangostana 6 plants.

Orchid from Tobago 2 plants.

Monodora grandiflora 1 plant.

Dypsis madagascariensis 1 plant.

Cyrtostachys lakka 1 plant.

Artocarpus incisa 1 plant.

Mauritzia palm 1 sack seed.

Borassus flabellifer 2 seeds.

Sweet Lime 12 seeds.

Portlandia grandiflora 6 seeds.

Barringtonia speciosa 2 seeds.

Cocos amara „..

Ptychorhaphis augusta

Strychnos nux vomica

Kentia Macarthurii

Brosimum calactodendron._.

Acanthoriza aculeata „

Ormosia dasycarpa

Saraca taipingensis

Attalea spectabilis

Caryota mitis

Lagerstroemia Flos-Reginae

Kleinhovia Hospita

Cassia emarginata

Dombeya masteriana

Dialium guineensis..

Thrinax Morrissii

Chrysalidocarpus lutescens..

Hyophorbe verschaffeltia

Dalbergia lanceolaria

Euterpe edulis

Myristica fragrans

Berry a ammonilla

Colvillea racemosa

Pongamia glabra

Thrinax parviflora

Carica papaya from Mar-
tinique

Carica papaya from San
Domingo

Sabal umbraculifera

Latania Commersonii

Bertholletia excelsa

Persea americana _

(Early

1 seed.
8 seeds.

1 pound seeds.
6 seeds.

6 seeds.
6 seeds.
^ pound seeds.

3 seeds.

2 seeds.

\ pound seeds.
12 seeds.
1 ounce seeds.

1 pod seeds.

\ ounce seeds.

2 ounce seeds.
2 ounce seeds.
6 seeds.

12 seeds.

2 ounce seeds.

4 ounce seeds.
12 seeds.

2 ounce seeds.
1 ounce seeds.
6 pods seeds.

12 seeds.

1 ounce seeds.

1 ounce seeds.
\ ounce seeds.

3 seeds.

2 fruits.
6 fruits.

Martinique)

In addition to these larger lots of plants, many important introductions
have been made from widely separated parts of the tropics and from the
United States Department of Agriculture, which maintains a staff of
explorers who travel in the interests of plant introduction. Close
cooperation exists between the Department and the Canal Zone Gardens.

Plant Dissemination.

The dissemination of plants that have been found to be of value for
economic or for ornamental purposes, must be considered as the com-
plement and counterpart of the work of plant introduction. This
applies also to plants that have not yet proven their worth but which

20

must be tried, in various conditions, before their merits can be known.
Therefore, it becomes necessary to maintain nurseries for the propagation
of plants in numbers sufficient to be sent out to the different parts of the
Isthmus. In fact the plants from the nurseries at the Gardens are
being sent to several of the neighboring republics. For distribution
purposes, these plants and seed stocks divide themselves into two
general classes, including first those that have been more or less tried
out, for which there is a popular demand, such as the varieties of oranges,
grapefruit, mangoes, avocados, and some other fruits, as well as very
many ornamentals. The second class includes quite new things on
which it is desired to get data from a wide range of conditions. These
are represented at present by such things as abaca, Hevea rubber trees,
and the recently introduced figs, grapes, and rices. Plants or seeds of
this class are usually placed, in small quantities, free of charge, in
localities and with parties where the chances seem best for the acquiring
of the desired data.

Plants of the first group also were formerly given away without cost
but there are so many of these called for in this country, where there are
no commercial nurseries handling such stocks, that the work became
limited by the extent of the funds which it seemed justifiable to put into
such work, in view of the fact that every dollar so spent out of the allot-
ments was a dollar taken out of the permanent development of the
Gardens. Early in the history of the Gardens, it was found necessary
to make a small charge for plants, and during the year just closed an
arrangement was made for the establishment of this phase of the nursery
work of the Gardens on .a self-supporting basis. This was done by the
setting up of a revolving fund; the charging of such prices for nursery
stock as are believed to cover the cost of production; and the return to
the revolving fund of all income from sales, which thus becomes avail-
able for use in producing further nursery stocks.

The plan, as outlined, appears to have been working out quite
satisfactorily. The demand for the nursery products is constantly
increasing and comes from an ever-widening circle. The quality of the
nursery stock is becoming better each year and every effort is being
made to send out only clean and healthy stock. For nearby points,
the trees removed from the nursery row with a ball of soil, are shipped
in open boxes. For long distance shipment of citrus trees, a nursery-
man's crate is used.

The Mango.

Some of the experiments in the control of the flowering season of the
Mango which were recorded in the Annual Report of these Gardens for

21

the year 1928, have been continued. During the year just closed, the
girdling process was applied to one or more branches of each of several
young Sandersha mango trees that had been producing some fruit for
about two years. The purpose, again, was to determine whether such
treatment would result in flowering earlier in the season and thus in
the maturing of fruits before the beginning of the rains. The girdling
was done in October, 1928, by the removal of a complete ring of bark
about one inch wide, the wound being covered with paint. Practically
every branch so treated, flowered early and held partly matured fruits
at the regular flowering season, when other trees and the other branches
on these trees were beginning to flower. These results confirm those of
the preceding year in which the main trunk of a large old tree was girdled
and produced a heavy crop of early fruit. The same results, it will be
recalled, followed the root-pruning of two other trees. No experiments
in root-pruning were conducted during the year just closed.

These practices, it must again be stated, are not being recommended
for general use but are merely being tried experimentally, as a part of a
plan to determine whether such changes in the behavior can be brought
about. The practical application of any such results must be worked
out later. One of the problems in connection with any such practices,
is the possible injury to the tree. In this connection it may be recorded
that the very wide girdling of the trunk of tree No. 3, referred to in the
Report for 1928, has been completely bridged over in nearly the entire
circumference of the trunk, thus indicating the tremendous recuperative
power of the mango tree. On the other hand, it must be stated that one
or two of the girdled branches concerned in this year's experiments,
broke off at the girdle which may have been due in part to heavy bearing.
It is not thought that any girdle so wide as one inch will be necessary to
bring about the early flowering which is desired; nor should such branches
be permitted to carry an excessive amount of fruit. It is possible that
root-pruning may prove to be a more practical process to bring about the
same results.

The fruiting season, which is at its height as this is being written,
is making it possible to get valuable data on many varieties, and it is
already possible to begin the eliminating process which must always result
from a variety collection. This is the whole purpose of a variety test,
to discover those forms which are of greatest value and to eliminate
those that are worthless or unadapted to local conditions. In this
connection, it must be remembered that a variety of any fruit might be
considered passable or even good, if there were not other varieties that
so far excel it or are so much better adapted to the conditions that the
less worthy must give place to the better.

22

On this basis, even at this early stage in the history of the orchard, it is
possible to establish three lists of the varieties of mangoes in the orchard.
One of these may be called the suspended list, another the present choice,
and a third consisting of those that must be further studied before ad-
judgment can be passed on them. Some of these are of great promise.
The present choice, in which the results attained thus far give more
confidence than in any other, is that to which we have given the name
Fairchild. The following is a brief description:

Mango variety Fairchild. — (Plate VII.) Fruit of medium size,
averaging less than three-fourths of a pound; form ovoid, sometimes
pointed; skin thin, clear bright yellow; flesh light golden yellow just be-
neath the skin and becoming of deeper color towards the seed, entirely
tree from fiber and of most delicious flavor; seed small, of the same
general outline as the fruit, polyembryonic. One of the most important
of the characteristics of the fruit of this variety is its high degree of resis-
tance to anthracnose to which it appears to be almost immune.

Origin and History. — The Fairchild mango is a selection from the lot
of seedlings which were introduced into the United States under the
S. P. I. number 11654, by Dr. David Fairchild, then Chief of the Office
of Foreign Seed and Plant Introduction. The seedlings were grown
under the general designation "Saigon" mango as they had been intro-
duced from Saigon, Cochin China. At an earlier date, Dr. Fairchild
had introduced seeds from Cambodia, French Indo-China, under the
general group name, Cambodiana, expecting, in the case of both in-
troductions, that some varieties of special merit would be found among
the seedlings. Although this race of mangoes from Indo-China is poly-
embryonic and therefore reproduces its characters by seeds much more
accurately than do the East Indian mangoes, there is nevertheless, a
sufficiently marked variation to have given rise to different forms,
some of which are not desirable. One of these is of green color when
ripe and is quite subject to injury by anthracnose. It is unfortunate
that the several forms have all passed more or less indiscriminately
under the two names, Cambodiana and Saigon. One of the seedlings
which originated in Florida from the first lot of seeds introduced, was
given the group name Cambodiana, which still further complicates the
matter. The present selection from the progeny of the second lot of
seeds (the Saigon seedlings) has been given the name Fairchild, in honor
of the distinguished explorer for plant introduction, to whom credit is
due for the introduction of the seed from which all of these varieties
have sprung, and likewise for a very long list of most valuable plant
immigrants.

p. 22— a.

23

Although the Fairchild does not excel all others in point of flavor,
texture, and appearance, it stands very high in relation to all of these
characters and excels in its resistance to mango anthracnose, producing
comparatively clean fruit even in rainy weather and without the appli-
cation of any fungicide. So far as can be concluded from two or three
years of bearing, the trees appear to be vigorous and productive while
the fruit is almost entirely free from fiber and of delicious flavor. Other
varieties, such as the Pairi, may take rank with it, if sufficient and
economical methods are developed for the control of anthracnose. There
is need of a systematic study of the use of fungicides under local con-
ditions, but the frequent torrential rains during the mango season,
render the use of the ordinary fungicides very difficult and rather
ineffective.

The suspended list includes the following:

Sandersha, Juan Mina, Ancon No. 2, Rosa, Corozal No. 546, Costa
Rica No. 11.

Sandersha, although handsome in appearance, when free from disease,
and also a heavy producer, has little to recommend it in point of texture
or flavor, and is so extremely subject to anthracnose that since the rains
began scarcely a single fruit has ripened without splitting and decaying.
The disease appears to affect varieties differently, but Sandersha splits
longitudinally and decays. Because it has little to recommend it, the
Sandersha will not be extensively propagated at present.

Juan Mina is a fibrous mango probably of local origin, having a good
flavor but too much fiber for any commercial variety. It is also subject
to anthracnose. Since there are others that excel it in all respects, there
appears to be no sufficient reason to propagate it.

Rosa has only its beauty to recommend it. The fruit is certainly
handsome in form and color, but it is too fibrous and of indifferent flavor.

Corozal (tree No. 546) is extremely precocious and prolific and is
worthy of a place in a breeder's collection for these characters, but the
flavor and texture are much below par.

In the case of the so-called suspended list, which will be augmented
each year as further data become available, it is intended that one or
two trees of the varieties will be retained but the others will be top-
grafted to better kinds. If still further observations confirm the present
estimate of these fruits, most of them will be discarded.

The list of those on which no judgment can be passed need not be
given here in full, as it contains all of the other mangoes at the Gardens,
most of which have been mentioned in earlier reports. There are in this
list some varieties of which much may be expected. Among the most
promising is the Pairi (Syns. Paheri, Pirie, Pyrie). This is one of the

24

Bombay or Alphonse group. It is almost entirely free from fiber so that
the seed usually can be slipped out of the fruit, leaving the latter in
halves. The aroma is unique and enticing. If ripened in dry weather
and hence free from anthracnose, the fruit is handsome, with a scarlet
blush on the exposed side. Fortunately the variety is not so subject
to anthracnose as are many others, and it may be possible to protect it
quite satisfactorily with fungicides. In flavor, Pairi is considered by
many to be the most delicious of all mangoes.

Pineapples.

The little field of about 5,000 plants of pineapple of the Spanish (Red
Spanish) variety, mentioned in the Report of 1928, has been fruiting
freely. At the time of this writing, just 21 months from the date of
planting, the first crop has not been completely harvested. The
variety appears to have met with favor in the local market. It was
introduced because of its adaptability to long distance shipment, and
because it is well known in the eastern United States markets. Several
thousand plants are available for distribution.

The Queen, sometimes known as Montufar (Plate VIII), has made
an unusually good growth and yield for this variety. The fruits have
proved to be extremely popular and nearly all those who have tried
them here have pronounced the Queen the most delicious pineapple
that they have ever eaten. The fruit, as grown here, has been of medium
size, with rather prominent ''eyes" or fruitlets, and light golden-yellow
flesh, free from fiber, tender, crisp, and sufficiently juicy. It is impor-
tant that the fruit be eaten before it has lost all of its green color, as fully
colored fruit is likely to be over-ripe. A small supply of planting
material of this variety also is available.

The variety, Milagro, introduced from Ecuador, is proving to be of
much interest because of its superior flavor, abundant juice, and its
freedom from spines on the leaves. Even the Cayenne, which is fre-
quently called the "smooth" Cayenne, has some spines near the tips of
the leaves but spines are rare or entirely absent on the leaves of the
Milagro. Comparing this variety with Cayenne in other respects the
following differences may be noted.

Cayenne. Milagro.

Exterior color Dark golden yellow. Straw color.

Color of flesh Light golden yellow. Cream.

"Eyes" Small, flattened. Large, more elevated.

PLATE VIII.

!:kfe fcj

f . - - ^

• T 1

The Queen pineapple.

D. '1

25

The Milagro is undoubtedly worthy of very careful study and may
prove to be of large commercial importance in the pineapple industry in
general.

The Cayenne variety has been mentioned in the earlier part of this
report, in connection with the plant introductions from Hawaii. This
being the standard canning variety, arrangements have been made to
get several thousand plants so that the supply for distribution can be
increased more rapidly.

Sugar Cane.

In the introduction of this report, mention has been made of the pur-
poses of the work with sugar cane. A newly planted plot now contains
the following varieties:

Badila. Yellow Calidonia. M 36.

Hawaiian Uba. P. O. J. 36. D 74.

Kavangira. P. O. J. 213. H 107.

Lahaina. P. O. J. 979. H 109.

Merthi. P. O. J. 2714. H 8965.

Oshima. P. O. J. 2725. BH. 10 (12).

Striped Mexican. P. O. J. 2727. D 1135.

Striped Tip. U. D. 1. 26 C 250.

Tekcha. EK 28.

It is believed that a most useful service can be rendered by the intro-
duction of varieties and by propagating them for trial under plantation
conditions.

Rice.

Much the same may be said of rice as has been stated concerning
sugar cane. Many varieties of rice have been introduced and have been
grown for one or more seasons. Small trial lots of seed are being dis-
tributed and further plantings are being made at the Gardens to increase
the available stock for next year. The varieties now under test include
the following:

Canabungbong. P. R. 315. P. R. 402.

Dinagat. P. R. 318. P. R. 422.

Kinamaleg. P. R. 327. R. D. 234.

Kinarazon. P. R. 343. R. D. 239.

KLnastila. P. R. 358. R. D. 249.

Pinulot. P. R. 367. S. D. 117.

Pulupot. P. R. 388. S. D. 120.
Tuit hag Dalog.

26

Rubber Plants.

In a cooperative effort, in connection with the United States Depart-
ment of Agriculture, about 1,000 trees, from selected seeds of Hevea
braziliensis, have been grown at the Gardens for certain experiments
which the Federal Government is desirous of conducting. These have
made excellent growth and are a very fine lot of seedlings.

Drought Resistant Trees.

The severe and prolonged dry weather of the past season has called
attention to the remarkable resistance to drought exhibited by some
species of trees. Among those that have gone through the dry season
without any irrigation and have maintained themselves in healthy
appearance may be mentioned the Ohia, Mountain-apple or Malay-
apple, Eugenia malaccensis. This tree with" its thick, glossy, dark-green
foliage has not even drooped or appeared in a distressed condition at any
time through the dry weather. The fruit at this season was dry and
pithy and new growth was not being made, but the trees remained
handsome. With the coming of the rains, the Ohia bursts into new
growth, presenting beautiful reddish-brown foliage over the exterior
of the tree which changes to a light green and finally to the dark-green
color of the fully mature leaf. The young trees at the Gardens are 1 8
to 20 feet high, but fully grown trees reach a height of 50 to 60 feet.
The flowers which are produced on the interior of the trees are bright
red and showy because of the clusters of long stamens. The interior
of the tree at the flowering time has been described as "filled with a
delicate scarlet haze." The fruits, although of no commercial importance,
are of brilliant red color, very decorative, and quite refreshing.

The sapodilla,nisperoor naseberry, Achras sapotay\s another tree that
appeared well able to adapt itself to dry conditions. It had no appear-
ance of suffering from lack of water. Had it been in fruit, doubtless
water would have been necessary to mature the crop. This tree, a source
of chicle for the manufacture of chewing gum, is possibly native in this
region, but does not appear to have received here the full recognition
of the value of its fruits. These are about the size of a small peach, and
are russet in color, containing from one. to several seeds. When properly
matured they are indeed delicious, resembling in flavor a sweet pear.
Possibly the reason for the comparatively infrequent planting of this as
a fruit tree may be the tardiness of the seedlings in coming into bearing, and
also their variability in bearing habit. In the Orient, where the sapodilla
is an introduced species, it is much more highly prized. In the Philip-

27

pines, where the fruit is known as the chico, the tree is propagated by
air-layering or Chinese layering almost exclusively, which results in
fruitfulness at an early age. It is one of the most profitable fruit trees
grown by the Filipino farmer. Here in Panama, the propagation of the
choicest sapodillas should receive more attention while the tree also
merits a place as an ornamental, expecially because of its apparent
resistance to drought.

Another of the outstanding drough-resistant trees, judged by its
performance in several different parts of the Gardens during the past
season, is the Acacia auriculae} ormis. There appears to be little infor-
mation in the available literature concerning this species of Acacia,
which was introduced by the United States Department of Agrucilture
under the S. P. I. No. 59,672. It is said to be a small tree, native of
Australia. The trees were received at Summit in 1925, and were planted
out in August of 1 926. Thus, with less than three years in their permanent
position, they have attained a height of 12 to 15 feet. During the last
season, without the application of any water, these trees showed no
evidence of injury, remaining green and unwilted.

Among other trees in the Gardens which seem to endure well the dry
weather are the mango, the beefwood or "Australian Oak," Casuarina
equisetifolia, and the African Tulip tree, Spathodea campanulata. To
what degree the application of water to mango trees, during heavy fruit-
ing, may be beneficial has not been determined. It is probable that it
would be necessary to use water if the trees are ready to mature fruit in
dry season.

Although there are these and a few others that can maintain them-
selves in health without irrigation during the dry season, there are many
that can not survive without applied water, and many more that are
retarded seriously in their growth.

Town and Roadside Plantings.

The Agronomist, on request, acts in an advisory capacity in the
matter of the making of new plantings of trees or shrubs in the Canal
Zone towns, and also in relation to the care of older plantings. The
principal new plantings recommended for Balboa and Ancon during the
year were on the slope above Cascadas Road, in view from the Adminis-
tration Building; and also in the grounds surrounding the United States
District Courthouse. A few plants have been planted in various other
places as needed. On the slope above Cascadas Road, the plantings
were chiefly of handsome flowering trees and shrubs. Among these are
several trees of the "Pink and White" Shower, Cassia nodosa, which

28

produces about May and June, a great profusion of flowers resem-
bling a display of apple blossoms, but unlike the apple, this tree continues
in flower for many weeks. (Plate IX, Figure I.) It is one of the most
beautiful of flowering trees. Several trees of Cassia multijuga were also
included. This is a tree of medium size producing its brilliant yellow
flowers at a time when the Cassia nodosa is not flowering. On the
point of the hill, there was planted a Jacaranda mimosifolia, a tree
with very delicately cut foliage and loose panicles of beautiful blue
flowers. It is classed among the best of the flowering trees. At the end
of the slope near Heights Road, there was planted a tree of the native
species "Alanza" or "Salamo," Calycophyllum candidissimum. This tree,
which grows to a height of 50 feet or more, is familiar to most residents
of the Isthmus by its profusion of white bracts at flowering time which
cover the tree almost completely and persist for many weeks. Groups
of the Purple Wreath, Petrea volubilis, were planted on the lower part
of the slope. This shrub or vine, during the dry season, is clothed with
elongated terminal racemes of most magnificent blue or purple color,
making it one of the most striking and attractive of tropical shrubs at
that time of the year. During the rest of the year it is rather incon-
spicuous. Other plants remommended for this locality include Lager-
stroemia flos-reginae, Warscewiczia coccinea, a native tree with brilliant
red bracts like those of the Poinsettia, and several others.

On the grounds surrounding the Courthouse were planted some
Triplaris americana, a native species, with purplish red flowers on the
pistillate tree, appearing in the dry season and persisting for several
weeks. Here also were placed a Pride of India, Largerstroemia flos-
reginae, a Calophyllum inophyllum sometimes called Palo Maria, a
Chrysalidocarpus lutescens^ the Cuban palm and other handsome trees.

In Xew Cristobal the plantings have been more general because of the
laying of new streets and the building of new cottages. In the case of
street trees it has always been recommended to confine the plantings to
one species on each street, or at least for several blocks. Exceptions
to this are made where temporary, rapidly-growing trees, can be inter-
planted with those of slower growth but of more permanent character.
The African Tulip tree, Spathodea campanulata, is well adapted to use
in such interplantings, as it very quickly forms a shade and is handsome
in appearance when young, but loses its beauty as it grows older, and can
then be cut down to make room for its more permanent neighbors. A
species of the "Australian Oak" or "Ironwood" tree, Casuarina, has
been chosen for one street, as these trees appear to do well in that
locality. Another street is planted with Triplaris americana, and another
with Warscewiczia coccinea, two native species mentioned above. The

PLATE IX.

Fig. 1. — Cassia nodosa infljwar.

Ik

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Fig. 2. — Interior view of plant house showing type oi construction.

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p. _'8 b.

29

latter two trees are more or less experimental as street trees, but are
worthy of a trial because of their beauty when in flower. It has been
recommended that the side of Ninth Street, next to the sea, be planted
with Ficus nitida, a banyan-like tree of great vigor and beauty, and well
known to the residents of the Isthmus because of the plantings so general-
ly admired on Roosevelt Avenue in Balboa. This tree requires wide
spacing, and there are few streets in the Canal Zone wide enough to
give room for its full development. Ninth Street, on the sea side,
affords a good opportunity.

Some important lessons for future planting and for the care of the
street trees arise out of the observations of the year. The Corotu, or
Ear-tree, Enterolobium cyclocarpum, is one of the most majestic of the
trees that have been planted for shade in the Zone. The past year has
called attention to a weakness in the construction of this tree which
makes it quite vulnerable in storms. Some trees have split due to the
narrow angle in the formation of the branches, at their junction with the
main trunk, or the tree may be so divided that two branches are of
equal size. These narrow-angled branches easily split off from the tree.
Plate X shows this formation and the results. Not only are such
branches likely to split off, but the cavity in the angle of attachment is
often so deep as to collect water where mosquitoes breed and, in dry
season, leaves and other debris collect there and harbor ants and termites.
These difficulties may be overcome in very young trees by judicious
pruning, removing all such narrow-angled branches and, if necessary,
cutting back the main trunk at the desired height and then forcing
out branches at wider angles.

A new difficulty, with the Corotu trees, appeared during the dry
season when the trees were out of foliage. An insect appeared and multi-
plied in such numbers as to completely cover 10 or 15 feet of the
outer ends of the branches. This insect, which does not seem to have
been observed here to any appreciable extent in earlier years, was sub-
mitted for identification to Mr. James Zetek, Associate Entomologist
of the Federal Bureau of Entomology, stationed at Balboa. Mr.
Zetek identified the insect as Poeciloptera phalaenoides of the family
Flatidae. Not only did these insects injure the trees, but the excessive
exudations of honey-dew or similar substance and its dropping on
clothing and automobiles caused annoyance to residents. Several
applications of an oil spray were made by the District Quartermaster
before the attack subsided.

In the selection of street trees, their habits of defoliation should
be kept in mind. Some trees, as the Corotu, or Ear-tree, and Dillenia
indica shed their leaves during the dry season and thus afford very little

30

shade at a time of year when shade is most needed. It is to be remem-
bered however, that the shedding of the leaves is an adaptation to
dry conditions and a tree should not be eliminated from the desirable
list for this cause alone.

Synthetic Manures.

The Canal Zone towns are models of cleanliness and sanitation. A
constant warfare is kept up against flies as a part of the necessary
sanitary measures. The use of stable manures in vegetable gardens,
flower gardens, or about trees in the lawns, always introduces the hazard
of providing a place for flies to breed. All manures so used are first
stored in concrete pits long enough to insure the destruction of any
eggs or larvae, but the material is often subject to reinfestation when
again exposed, thus making objectionable the use of stable manure in
the towns. But the gardens, without some organic manures would soon
fail. To meet this situation, it was recommended that a trial be made
of synthetic manure, prepared by causing the rapid decomposition of
grass, weeds, and leaves. Of these there is always an abundance which
must be gathered up and hauled away from the towns. If placed in
piles and kept wet they would in time decompose, but more rapid
breaking down may be brought about by the use of a small amount of
material, containing large numbers of nitrifying bacteria, and well mixed
with the trash, as it is built into a long compost heap. In the case in
question, a proprietary preparation was used by the District Quarter-
master of Balboa and Ancon, who carried out the suggestion. The
results were reported to be satisfactory. The break down was rapid, the
decomposed material served well as a fertilizer, and is reported to have
been free from infestation by flies. It is not impossible, however, that
this material may be more or less subject to infestations.

Buildings.

Both ranges of plant houses at the lower end of the Gardens have now
been rebuilt. The Annual Report for 1928 mentions chiefly the south
range, including potting shed, concrete soil bins, soil sterilizer, a glass
house, and permanent shade houses of pipe construction. During the
year just closed, the north range has been rebuilt, consisting of two small
sheds or work rooms, and several part-shade houses of slat construction,
with grooved slat roof so as to reduce to a minimum the dripping of
water upon the plants. Although this type of construction is less
permanent than that in which galvanized pipe is used, it is also very

31

much less expensive and regulates more accurately the amount of shade.
It remains to be determined, how long the wood will last and whether
it will prove to be an economical construction. For bench supports in
all of these slat houses, slightly damaged vitrified pipe has been used,
this being more permanent than wood, resisting water and termite
attacks. It also costs only the hauling as these pieces of new pipe
with slightly chipped shoulders that can not be made water-tight are
useless in sewer construction and must be condemned. Being of uni-
form size, new and clean, the appearance is quite satisfactory. Plate IX,
Figure 2, shows the general type of construction of these shade houses.

The Needed Irrigation System.

In the Annual Report for 1928, the need of an adequate irrigation
system was presented. The dry season just passed was long and severe,
resulting in much damage to some of the plants. The avocado orchard
serves as an illustration in point. This orchard, which ought to have
been bearing fruit for the past two years, has not yet produced a basket
of fruit, and has none worth mentioning this year. Thus two or three
years of fruitfulness and of valuable experimental data have been lost,
all of the trees have been seriously retarded in their growth and some
have died, as a result of insufficient water, although such water as it
was possible to get to them was applied. As this condition is typical of
many parts of the Gardens, it is gratifying to be able to state that plans
for establishing an adequate irrigation system are now receiving con-
sideration. Several plans have been presented by the engineers, and it
is hoped that funds will be made available to relieve the situation before
the next dry season.

MR 20846— Panama Canal— 12-23-30—1,500

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UNIVERSITY OF FLORIDA

3 1262 09079 7126

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